Food steaming method and apparatus

ABSTRACT

A method and apparatus for steam cooking food items in two consecutive steps whereby the food items contained in a food carrier are first preheated in water in a container which is being heated by a heater. After the food items are at or near the cooking temperature, the food carrier is raised above the water and into steam. A cover may be placed on the container so as to retain the steam within the container.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/211,828 filed on Apr. 4, 2009 by the presentinventor, and entitled “IMPROVED FOOD STEAMING METHOD AND APPARATUS”,the entire contents of which are hereby incorporated by reference hereinfor all purposes.

FIELD OF INVENTION

This invention relates to method and apparatus for steam cooking food.

BACKGROUND OF THE INVENTION

Steam cooking of food, particularly steam cooking of certain vegetablesis a well known art. Commonly available devices for this purpose aregenerally known as “Vegetable Steamers”. A simple “Vegetable Steamer”typically consists of a cooking container with a “Basket” that fitswithin the container closing its opening, and a cover that fits theopening of the basket. The basket has a perforated bottom and may alsohave a perforated sidewall. These perforations are small enough toprevent food particles from passing through. They are also sufficientlylarge and numerous to allow steam generated by water being boiled in thecontainer to pass through the perforations and into the basket. To steamfood, a quantity of water is placed into the cooking container, which isplaced on a heater where the water is made to boil and produce steam.Food to be steamed is placed into the basket, the basket is placed intothe container producing steam, and the cover is placed on the basketsubjecting the food in the basket to continuous steam until it hasattained a desirable edible state.

Many specific devices exist, all generally based on the common principleof steaming food/vegetable items from room temperature, or a frozenstate, until they are deemed to be edible by the cook.

The method of steaming vegetables employed by state of the art“Steamers” can be characterized as a single step method. The basketcontaining the food initially at room temperature, or in a frozen state,is immersed in steam and held within this steam until the food items aredeemed to be cooked adequately.

These conventional steamers suffer numerous problems and disadvantages,such as variable or unpredictable cooking times and uneven cooking. Inview of these and other problems, while steaming food may be anutritionally desirable process, steaming may not be used as readily asit might be if results were predictable, reliable and easily attained.Accordingly, the inventor has recognized a need for new or improvedmethods and apparatus for steaming food items.

SUMMARY

According to one aspect of the invention, there is a method of steamcooking. The method includes the steps of placing a food item in water;preheating the food item in the water, by heating the water, until thefood item attains a preheated condition; boiling the water such thatsteam from boiling water contacts the food item; and cooking the fooditem in steam from the boiling water until the food item attains acooked condition.

The preheated condition may be defined by commencement of the waterboiling while the food item is in the water.

The water may be heated so as to boil the water prior to placing thefood item in the water such that placing the food item in the boilingwater temporarily stop the water from boiling. Accordingly the preheatedcondition may be defined by recommencement of boiling while the fooditem is in the water.

The preheated condition may correspond to the food item attaining atemperature approximately equal to the boiling point of water.

The steam may have a nominal steam temperature, and the cooked conditionmay be defined by cooking the food item for a predetermined time at thesteam temperature.

According to another aspect of the invention, there is a method of steamcooking. The method includes the step of placing water in a firstcontainer, and placing a food item in a second container configured toretain the food item. The second container has perforated walls and issized and shaped to be moveable within the first container between alower position and an upper position. The method also includes the stepsof placing the second container, and the food item therein, within thefirst container in the lower position such that the water passes throughthe perforated walls in the second container so as to contact the fooditem; and preheating the food item in the water, by heating the water,until the food item attains a preheated condition. After the food itemattains the preheated condition, the method includes the steps of movingthe second container to the upper position within the first containerand above the water, boiling the water such that steam from boilingwater passes through the perforated walls in the second container so asto contact the food item, and cooking the food item in the steam untilthe food item attains a cooked condition.

According to another aspect of the invention, there is a steamingapparatus. The apparatus includes a stand sized and shaped to fit intoan opening of a first container configured to retain heated water. Thestand has a base for being placed on a bottom surface of the firstcontainer. The apparatus also includes a second container configured toretain a food item. The second container has perforated walls and issized and shaped to fit in the opening of the first container. Thesecond container is moveable within the first container between a lowerposition such that the heated water within the first container passesthrough the perforated walls so as to heat a food item retained withinthe second contain, and an upper position such that the second containeris located above the heated water within the first container and steamfrom the heated water passes through the perforated walls so as to heatthe food item retained within the second container. The apparatus alsoincludes a coupler for coupling the stand to the second container. Thecoupler is configured to allow the second container to move between theupper and lower position.

In some embodiments, the apparatus may also include a lifter coupled tothe second container for raising and lowering the second container.Furthermore, the coupler may include a vertical member coupled to anedge of the stand so as to extend upward along a side of the secondcontainer, and a detent. The vertical member has at least one tooth. Thedetent is coupled to the second container for engaging the at least onetooth of the vertical member so as to retain the second container in aposition corresponding to engagement of the detent and the at least onetooth. The lifter is configured to allow the detent to selectivelyengage and disengage the at least one tooth of the vertical member.

In some embodiments, the coupler may include a shaft coupled to acentral portion of the stand and a bushing coupled to the secondcontainer and having a hollow end for slidably receiving the shaft. Theshaft extends upward through an aperture in the second container and hasat least one tooth. The bushing is received within the shaft through theaperture in the second container. The coupler may also include a detentcoupled to the bushing for engaging the at least one tooth of thevertical member so as to retain the second container in a positioncorresponding to engagement of the detent and the at least one tooth,and a lifter coupled to the bushing for sliding the bushing along theshaft so as to raise and lower the second container between the upperand lower positions when the detent disengages the at least one tooth.

According to another aspect of the invention, there is an automaticsteaming apparatus. The apparatus includes a first container configuredto retain heated water and having a rim defining an opening, and asecond container configured to retain a food item and having perforatedwalls. The second container is sized and shaped to fit in the opening ofthe first container and is moveable within the first container between alower position such that the heated water within the first containerpasses through the perforated walls so as to heat a food item retainedwithin the second container, and an upper position such that the secondcontainer is located above the heated water within the first containerand steam from the heated water passes through the perforated walls soas to heat the food item retained within the second container. Theapparatus also includes a lifter mechanism coupled to the first andsecond containers for automatically moving the second container from thelower position to the upper position after the heated water within thefirst container preheats the food item to a preheated condition.

The apparatus may include a temperature sensor in communication with thelifter mechanism. The temperature sensor is configured to measure thetemperature of the water in the first container. Furthermore, thepreheated condition corresponds to the temperature sensor measuring atemperature approximately equal to the boiling point of water.

According to another aspect of the invention, there is an automaticsteaming apparatus. The apparatus includes a first container configuredto retain heated water and having a rim defining an opening, and asecond container configured to retain a food item and having perforatedwalls. The second container is sized and shaped to fit in the opening ofthe first container and is moveable within the first container between alower position such that the heated water within the first containerpasses through the perforated walls so as to heat a food item retainedwithin the second container, and an upper position such that the secondcontainer is located above the heated water within the first containerand steam from the heated water passes through the perforated walls soas to heat the food item retained within the second container. Theapparatus also includes a handle coupled to the second container formoving the second container between the lower position and the upperposition. The handle includes a stepped portion configured to at leastpartially retain the second container in the upper position.

The handle may also include a hook for engaging the rim of the firstcontainer so as to at least partially retain the second container in theupper position.

Other aspects and features will become apparent, to those ordinarilyskilled in the art, upon review of the following description of someexemplary embodiments.

DRAWINGS—FIGURES

The drawings included herewith are for illustrating various examples ofmethods and apparatus of the present specification and are not intendedto limit the scope of what is taught in any way. In the drawings:

FIG. 1 is a schematic diagram that illustrates a first stage of a twostage steam cooking method according to an embodiment of the invention,wherein a food item is in a lower position and is immersed in water forpreheating the food item, for example, to or near a food cookingtemperature of 100° C.;

FIG. 2 is a schematic diagram that illustrates a second stage of the twostage steam cooking method of FIG. 1, wherein the preheated food item isin an upper position and is raised held in a steam zone for steamcooking the food item to a desired state of completion;

FIG. 3 is a sectional view of an apparatus for steam cooking a food itemin two stages according to another embodiment of the invention, whereinthe food item is in a lower position;

FIG. 4 is a sectional view of the apparatus of FIG. 3, wherein the fooditem is in an upper position;

FIG. 5 is a sectional view of an automatic food steaming apparatus forsteam cooking a food item in two stages according to another embodimentof the invention, wherein the food item is in a lower position;

FIG. 6 is a sectional view of the automatic food steaming apparatus ofFIG. 5, wherein the food item is in an upper position;

FIG. 7 is a sectional view of another food steaming apparatus for steamcooking a food item in two stages according to another embodiment of theinvention, wherein the food item is in a lower position;

FIG. 8 is a sectional view of the food steaming apparatus of FIG. 7,wherein the food item is in an upper position;

FIG. 9 is a sectional view of another food steaming apparatus for steamcooking a food item in two stages according to another embodiment of theinvention, wherein the food item is in a lower position;

FIG. 10 is a sectional view of the food steaming apparatus of FIG. 9,wherein the food item is in an upper position;

FIG. 11 is a flow chart illustrating a method of steaming a food itemaccording to another embodiment of the invention; and

FIG. 12 is a flow chart illustrating another method of steaming a fooditem according to another embodiment of the invention.

DETAILED DESCRIPTION

The inventor has recognized that conventional methods of steaming andsteamers do not distinguish between two separate and functionallydifferent stages in the overall steaming process. Before food can “cook”or “steam cook” the food temperature must rise to a cooking temperaturewhich is generally at or near the temperature of steam, nominally 100°C. Before this temperature is reached, no or minimal cooking takesplace.

This “preheating” stage is problematic in the overall steaming processsince it is indeterminate and leads to difficulty in timing thecompletion of the overall process and leads to unpredictable and erraticresults.

For example, it has been experimentally determined that green beans oncethey have reached the cooking temperature will steam cook quiteconsistently to a personal preference of taste and texture in nine (9)minutes. This cooking time tends to be repeatable with the same lot ofgreen beans.

If these same green beans are steamed in a state of the art steamer fromany other state than described above, the time required to achieve thesame degree of taste and texture tends to be indeterminate and extremelyvariable.

Preheating time variability and unpredictability, which results infrequently unsatisfactory results achieved by state of the art steamersis inherent in the following.

The time required to heat food items from room temperature to the steamcooking temperature within the steamer is indeterminable and introducesa level of uncertainty in the overall time required to steam the fooditems adequately and uniformly.

If frozen foods are placed into a steamer directly, they need to thawfirst before they can start to heat towards the cooking temperature. Thetime required to thaw these food items before they can heat towardssteam cooking temperature introduces an additionally level ofuncertainty in the overall time required to steam the food itemsadequately and uniformly.

Small food items tend to heat quickly to the cooking temperature andcook prematurely, whereas large food items tend to heat slower and cookvariably. Steaming a mix of larger and smaller food items generallyproduces variability in both taste and texture of the large and smallpieces.

A deep bed of food items tends to heat variably, where the lower andouter layers directly exposed to the steam generally heat first andstart to cook, while upper and interior food items tend to heat laterand variably, depending on location and size of the food items.

Very large food items, such as whole mature carrots and potatoes, tendto be difficult to steam consistently because steam needs to condense onthe outer surface of the vegetable before it can release its latent heatto the surface of the vegetable for conduction to the interior of thevegetable, which tends to slow the preheating process because the layerof condensation needs to lose heat through thermal conductivity to thecentre of the vegetable before more steam can condense. Accordingly, theexterior of the food item tends to reach a cooking temperature early andmay start to cook while cooking of the interior of the food item isdelayed. The ultimate result is that large food items tend to haveovercooked exteriors with undercooked interiors.

Accordingly, the inventor has recognized a need for methods andapparatus of steam cooking food in two-stages, namely a first preheatingstage and a second cooking stage.

A method of steam cooking food in two stages will now be described withreference to FIG. 1 and FIG. 2. Referring to FIG. 1, the method includesa first stage of preheating one or more food items 54 toward a cookingtemperature while the food items 54 are submerged in water 56 that isbeing heated in a container 70 by a heat source 62. As shown, the fooditems 54 are in a lower position L of the container 70 during the firststage.

The termination of the first stage occurs when the food items 54 attaina preheated condition. For example, the preheated condition may bedefined by the food items 54 attaining a predetermined temperature (e.g.approximately 100° C.) as measured by a thermometer 50 in the water 56,or by the commencement of the water 56 boiling, which may be visuallydetermined by an observer 52.

Referring to FIG. 2 the second stage begins after completing the firststage and includes steam cooking food items 54 in steam 60 until thefood items attain a cooked condition. For example, the cooked conditionmay be determined by cooking the food items 54 for a predetermined timeat the steam temperature.

As shown, the food items 54 are in an upper position U of the container70 during the second stage. The steam 60 may be retained within thecontainer 70 using a cover 72.

Referring now to FIG. 1, illustrated therein is a container 70 and afood carrier 64 used for the first or preheating stage of the method.Food items 54 are retained in the food carrier 64, which is placedwithin container 70 in the lower position L. The food carrier 64 hasopenings or perforations 66 in its surface or walls, which allows water56 to surround the food items 54. For example, the food carrier 64 maybe a wire basket, a strainer, or another perforated container. The water56 in the container 70 is heated by a heat source 62, which transfersheat to the food items 54 through the water 56. Accordingly, the fooditems 54 are progressively preheated in tandem with the rise intemperature of water 56. The first stage may end upon commencement ofthe water 56 boiling. For example, the thermometer 50 may indicate thatthe temperature of water 56 is approaching the boiling point, oralternately, the boiling point of water 56 can be observed visually byan observer 52 through noting the rapid boiling agitation of the surfaceof water 56.

Referring to FIG. 2, illustrated therein is the container 70 and thefood carrier 64 being used for the second or cooking stage of themethod. Food items, which are now preheated in the first stage (e.g. toor near the steam cooking temperature), are lifted out of the water 56and into the upper position U above the surface of water 56, forexample, by lifting the food carrier 64 to the upper position U. If thewater 56 is not already boiling, the water is boiled to produce steam60, which may be retained within the container 70 by cover 72. The steam60 tends to surround the food items 54 in food carrier 64 by passingthrough the openings 66 and steam cooks the food items 54 until the fooditems attain a cooked condition. For example, the cooked condition maybe determined by cooking the food items for a time period indicated bytimer 68, which is set to signal completion of the second stage. Thetimer 68 may be set according to experience with the same or similarfood items previously determined to have reached a desirable taste andtexture in the set time period.

Referring now to FIG. 3 to 10, various steam cooking apparatus will nowbe described, which may be used to implement the method described above.

Referring now to FIG. 3 and FIG. 4, illustrated therein is a steamingapparatus 100 comprising a food carrier 164 and a stand 174, which maybe placed in a container, such as container 70. Food carrier 164containing food items 154 is supported by stand 174. Furthermore, thestand 174 is configured to move the food carrier 164 between the lowerposition L in the first stage as shown in FIG. 3, and the upper positionU in the second stage as shown in FIG. 4.

The apparatus 100 includes a coupler for coupling the food carrier 164to the stand 174 and for allowing the food carrier 164 to move betweenthe upper position U and the lower position L. In the illustratedembodiment, the coupler includes a vertical member 175 coupled to anedge of the stand 174 and a detent 184 coupled to the food carrier 164.The vertical member 175 has teeth 182 along a portion of its length. Thedetent 184 selectively engages one of the teeth so as to retain the foodcarrier 164 in a vertical position corresponding to the engage of thedetent and the tooth. For example, the vertical position generallycorresponds to the upper position U.

The apparatus 100 also includes upper guide 178 and lower guide 180,which are attached to the sidewall of food carrier 164. The upper andlower guides 178 and 180 slide along the vertical member 175 so as toguide the food carrier 164 along the vertical member 175 while moving itbetween the lower position L and the upper position U. For example,while the detent 184 engages one of the teeth 182, the lower guide 180allows limited additional horizontal freedom of motion such that detent184 may engage or disengage from teeth 184 and food carrier 164 may bemoved to and held at multiple retaining locations along the length ofthe vertical member 175. The food carrier 164 is held by the forceprovided by the weight of food carrier 164 and the pivoting effect ofupper guide 178, which provides loading to maintain firm contact betweenthe detent 184 and teeth 182.

The stand 174 has a base, which may include a horizontal element 176 andcross element 177, which generally defines a cross-shape. The baseprovides a firm footing for the stand 174 so that it may be placed andmaintain its horizontal orientation when placed into a container forsteam cooking.

The apparatus 100 also includes a lifter coupled to the second containerfor raising and lowering the second container. In the illustratedembodiment, the lifter is a lifter arm 188 coupled to food carrier 164,for example, through an attachment 194 mounted to the sidewall of foodcarrier 164. The lifter arm 188 can be used to lift the food carrier 164and simultaneously disengaging the holding action of detent 184 andteeth 182 such that food carrier 164 may be moved to and held at anyavailable detent position along the length of the vertical member 175.

The lifter arm 188 may be pivotally coupled to the attachment 194, suchthat the lifter arm 188 may be moved between a generally verticalposition and a generally horizontal position. In the vertical position,the lifter arm 188 can be used to move the food carrier 164 between theupper and lower positions. In the horizontal position, a lid can beplaced on the container. A pivot stop 196 is coupled to the attachment194 and limits the lowest pivotal position of lifter arm 188 when it isin the horizontal position.

The lifter arm 188 may include a grip 190 made of a suitable material toallow safe reduced temperature gripping of lifter arm 188.

Referring now to FIG. 3, the food carrier 164 is shown in the lowerposition L for preheating food items in the first stage. Lifter arm 188is oriented vertically to allow access away from the boiling water whenlifting the food carrier 164 from the lower position L to the upperposition U.

Referring now to FIG. 4, the food carrier 164 is shown in the upperposition U for steam cooking food items in the second stage. Lifter arm188 is pivoted to its lower generally horizontal position as determinedby the location of pivot stop 196 to reduce the overall height of theapparatus 100, which allows the cover 72 to be placed on the container70.

Referring now to FIG. 5 and FIG. 6, illustrated therein is an automaticfood steaming apparatus 200 for automatically steam cooking food itemsin two stages according to another embodiment of the invention. Inparticular, the automatic food steaming apparatus 200 is shown as anelectric appliance.

The electric appliance 200 includes a container 270 for retaining waterand a food carrier 264 moveable between a lower position L and an upperposition U within the container 270 as shown in FIG. 5 and FIG. 6respectively. The electric appliance 200 also includes a liftermechanism for automatically moving the food carrier 264 from the lowerposition to the upper position after the food item 254 attains thepreheated condition as will be described below.

In the illustrated embodiment, the lifter mechanism is coupled to thecontainer 270 at the centre of its bottom surface. The lifter mechanismincludes a bushing 205 and a rotating shaft 207 with rotary seals 206 atboth ends of the bushing 205 to prevent water penetration into bushing205. The upper end of shaft 207 is threaded into screw 202 while thelower end is configured to provide a contact coupling 216 with therotary drive provided by a motor 214, such as a gear motor.

The food carrier 264 is configured to fit within container 270 and ismoveable within the container 270 between the lower position L and upperposition U. For example, the centre of food carrier 264 has an internalscrew thread for engaging the screw 202. Accordingly, rotation of shaft207 clockwise or counter clockwise raises or lowers the food carrier 264between the lower position L and the upper position U.

In some embodiments, the lifter mechanism may have differentconfigurations. For example, the lifter mechanism may be a hydraulic orpneumatic cylinder, a spring operated by engaging or disengaging alatch, or any other suitable mechanism. Generally, the lifter mechanismis configured to automatically raise the food carrier 264 from the lowerposition to the upper position after the food item attains the preheatedcondition. The lifter mechanism may also be located in another positionother than at the centre of food carrier 264, for example, external towater container 270 or within cover 272.

The electric appliance 200 also includes an appliance housing 201 thatencloses a master controller 208 powered by electric power cord 218. Themaster controller 208 controls operation of the electric appliance 200,including the heater 262 and actuation of the lifter mechanism so as tomove the food carrier between the lower and upper positions. Forexample, after filling the container 270 with water, the appliance 200may be plugged in such that the master controller 208 turns on theheater 262. Then after, the food item attains the preheated condition,the master controller may actuate the lifter mechanism so as toautomatically raise the food carrier 264 from the lower position L tothe upper position U.

A temperature sensor 212 may be communication with the master controller208 for determining when the food item attains the preheated condition.For example, the temperature sensor 212 measures the temperature ofwater 256 in container 270 that is being heated by heat source 262. Inparticular, the temperature sensor 212 is coupled to the wall of thecontainer 270 for measuring the temperature of the water 256 through thewall. In other embodiments, the temperature sensor 212 may measure thetemperature of the water directly.

When the temperature sensor 212 measures a temperature at or near theboiling point of the water, the master controller 208 actuates thelifter mechanism so as to raise the food carrier from the lower positionL to the upper position U. For example, gear motor 214 receives powerfrom master controller 208 according to input instructions received fromthe temperature sensor 212 and/or an internal control program.

The electric appliance 200 also includes a touch screen 210, whichenables a user of the appliance 200 to determine the status of thecooking process and enables the user to input instructions to the mastercontroller 208 for setting specific cooking conditions for the food item254 being steam cooked. For example, the user may enter information thatdefines the preheated condition and/or the cooked condition. Inparticular, the user may input the amount of time that the food itemwill be cooked in the steam so as to define the cooked condition.Furthermore, the user may also input information to the mastercontroller 208 through the touch screen 210 to activate a specificprogram provided by master controller 208, for example, “cook greenbeans”, “cook potatoes”, or “manual override” (e.g. to raise the foodcarrier 264 to the upper position manually).

Referring now to FIG. 7 and FIG. 8, illustrated therein is a steamcooking apparatus 300 comprising a container 370 for retaining heatedwater 356, a cover 372 for covering the container 370 and retainingsteam 360 in the container 370 during the second stage, a food carrieror container 364 having openings 366 (e.g. a perforated container) forretaining food items 354, a lifter arm 388 (e.g. handle) coupled to foodcarrier 364, and a grip 390 on the lifter arm 388. Generally, the lifterarm 388 allows a user to move the food carrier 364 between a lowerposition L as shown in FIG. 7, and an upper position U as shown in FIG.8. Accordingly, the food carrier 364 and the lifter arm 388 aregenerally sized and shaped to fit within the container 370 such that thefood carrier 364 can be moved between the upper and lower positions.

Referring to FIG. 8, the lifter arm 388 has a stepped portion 352, whichallows lifter arm 388 to pass through a gap between cover 372 andcontainer 370 when the food carrier 364 is in the upper position and thecover 372 is on top of the container 370. The stepped portion 352 alsoat least partially retains the food carrier 364 in the upper position byengaging the rim of the container 370. In some embodiments, the lifterarm 380 may include a rim hook 350 on the stepped portion 352 forretaining the food basket 364 in the upper position U.

Referring now to FIG. 9 and FIG. 10, illustrated therein is a steamingapparatus 400 comprising a food carrier 464 and a stand 474, which maybe placed in any appropriate container with cover, such as containers 70and 370, and lids 72 and 372. The stand 474 is configured to move thefood carrier 464 between the lower position L in the first stage, andthe upper position U in the second stage.

In the illustrated embodiment, the food carrier 464 is an adjustablesized container, which includes a plurality of overlapping leaves 401pivotally coupled to a central hub portion 402. Pivoting or folding theleaves 401 upward about the central hub portion 402 causes adjacentleaves 401 to overlap more and decreases the diameter of the foodcarrier 464. Conversely, folding the leaves downward about the centralhub portion 402 causes adjacent leaves 401 to overlap less and increasesthe diameter of the food carrier 464. Each leaf includes perforation oropenings 466 to allow steam to pass through the openings 466 such thatthe steam contacts food items retained by the food carrier 464. In someembodiments, the food carrier 464 may have fixed, non movable legs onthe bottom of the food carrier for providing a space between the foodcarrier 464 and the bottom of a container, such as containers 70 and370.

The apparatus 400 includes a coupler for coupling the food carrier 464to the stand 474 and for moving the food carrier between the lowerposition L and the upper position U. For example, the coupler includes ashaft 406 coupled to the stand 474 and having teeth 408, a bushing 416coupled to the food carrier 464 that slidably receives the shaft 406, adetent coupled to the shaft 406 for engaging one of the teeth 408, and alifter or grip 422 coupled to the bushing 416 for raising and loweringthe food carrier 464.

The adjustable sized a flange 420 couples the bushing 416 to the centralhub portion 402 of the food carrier 464. Bushing 416 has a lower endcoupled to flange 420 and an upper end coupled to the grip 422. Stand402 comprises a base 404 and a shaft 406 centrally attached to base 404.Shaft 406 slides freely in bushing 416.

In the illustrated embodiment, the detent 414 is coupled to the outersurface of the bushing 416. Accordingly, the side of the bushing 416 hasan opening or slot 418 near its lower end to allow the detent 414 topass through the bushing 416 and engage the teeth 408 on the shaft 406.In some embodiments, the detent may be coupled to different portions ofthe bushing 416, for example, the internal bore of the bushing.

Generally, the detent 414 is biased toward engagement with the teeth408. For example, a leaf spring 410 having one end coupled to thebushing 416 and another end coupled to the detent 414. Leaf spring 410provides spring loading to detent 414 which biases the detent 414 toengage or interlock with the teeth 408 and thereby support food carrier464 above base 404 in a lower location L or an upper location U to allowthe steam cooking of food items in two stages as described above. Asshown in the illustrated embodiment, the detent 414 may be integrallyformed with the leaf spring 410 and may be an extension of the leafspring 410. In other embodiments, the detent 414 may be a separatepiece.

In the illustrated embodiment, the teeth 408 are located on one side ofthe shaft 406, while the other side of the shaft is generally smooth,which may facilitate moving the food carrier 464 between the upper andlower positions. Accordingly, the bushing 416 may be rotated between anengaged position and a disengaged position. When the bushing 416 isrotated to the engaged position, detent 414 engages one of the teeth 408so as to retain the food carrier 464 in a vertical position along theshaft 406. When the bushing 416 is rotated to the disengaged position,the detent 414 disengages the teeth 408 and is moveable along the smoothsurface of the shaft 406 such that the bushing 416 can slide freely upand down the shaft 406 so as to raise and lower the food carrier 464. Toagain establish a support position, the bushing 416 can be rotated tothe engaged position again such that the detent 414 engages orinterlocks with one of the teeth 408.

Accordingly, the apparatus 400 can be used for the two stage steamcooking method described above. Furthermore, the apparatus 400 can beused in different containers having different sizes while still allowingthe food carrier 464 to be moved between the upper and lower positions.

Referring now to FIG. 11, illustrated therein is a method 500 of steamcooking according to an embodiment of the invention. The method 500comprises a first stage 502 of preheating a food item in boiling orotherwise heated water, and a second stage 504 of cooking a food item insteam from boiling water.

The first and second stages 502, 504 may also include additionalsub-steps. For example, in the illustrated embodiment, the first stage502 includes steps 512 and 514, and the second stage 504 includes steps522 and 530, as will be described below.

Step 512 includes placing a food item in water. For example, the fooditem may be placed in a food carrier, such as food carriers 64, 164,264, 364, or 464 described previously, and the food carrier may beplaced in a container filled with water, such as containers 70, 270, or370 described previously.

In some embodiments, the food item may be placed in the water indifferent ways. For example, the food item may be placed in a basket,colander, or another perforated container. In some examples, the fooditem may be placed directly in the heated water, without a perforatedcontainer.

In some embodiments, the water is heated so as to boil the water priorto placing the food item in the water. Generally, placing the food itemin the boiling water temporarily stops the water from boiling. Forexample, the water may stop boiling because the food item absorbs heatfrom the boiling water.

In some embodiments, the food item may be placed in water that is coldor otherwise not yet boiling.

Step 514 includes preheating the food item in the water, by heating thewater, until the food item attains a preheated condition. Generally, thepreheated condition is defined by commencement of the water boilingwhile the food item is in the water. For example, in some embodiments,the food item is placed in water that is already boiling, whichtemporarily stops the water from boiling. Then the water is reheatedagain to the boiling point and the preheated condition is defined byrecommencement of boiling while the food item is in the water.

In some embodiments, such as when the food item is placed in water thatis cold, or not yet boiling, the preheated condition may be defined bythe initial commencement of the water boiling. Accordingly, the fooditem may be heated while contemporaneously brining the water to a boil.

In other embodiments, the preheated condition may be defined bydifferent characteristics or events. For example, the preheatedcondition may correspond to the food item attaining a temperatureapproximately equal to the boiling point of water, or preheating thefood item for a predetermined time.

After the food item reaches the preheated condition, the second stage504 begins at step 522, which includes boiling the water such that steamfrom the boiling water cooks the food item. In some embodiments, thewater may already be boiling, for example, when the preheated conditionis defined by the commencement or recommencement of boiling.

Step 530 includes cooking the food item in steam from the boiling wateruntil the food item attains a cooked condition. For example, the cookedcondition may be defined by cooking the food item for a predeterminedtime at a predetermined temperature. Furthermore, the predeterminedtemperature may be the temperature of the steam or a nominal steamtemperature. Generally, the steam temperature is approximately theboiling point of water, for example, about 100° C.

The predetermined time may depend on the food item being cooked. Forexample, some green beans tend to take approximately nine minutes tocook at a predetermined temperature of approximately 100° C.

Referring now to FIG. 10, illustrated therein is a method 600 of steamcooking according to another embodiment of the invention. The method 600comprises a first stage 602 of preheating a food item in boiling orotherwise heated water, and a second stage 604 of cooking a food item insteam from the heated water. The first stage 602 includes steps 610,612, 614, and 616, and the second stage 604 includes steps 620, 622 and630 as will be described below.

Step 610 includes placing water in a first container. For example, thefirst container may be similar to the containers 70, 270, or 370described previously.

Step 612 includes placing a food item in a second container configuredto retain the food item. The second container has perforated walls andis sized and shaped to be moveable within the first container between alower position and an upper position. For example, the second containermay be similar to the food carriers 64, 164, 264, 364, or 464 describedpreviously.

Step 614 includes placing the second container, and the food itemtherein, within the first container in the lower position such that thewater passes through the perforated walls in the second container so asto contact the food item.

Step 616 includes preheating the food item in the water, by heating thewater, until the food item attains a preheated condition. For example,the preheated condition may be defined by commencement of boiling whilethe second container is in the lower position such that the food item isin the water.

In some embodiments, the food item may be placed in water that isalready boiling, which may temporarily stop the water from boiling, forexample, because the food item absorbs heat from the boiling water. Thenthe water is reheated again to the boiling point and the preheatedcondition is defined by recommencement of boiling while the secondcontainer is in the lower position such that the food item is in thewater.

In other embodiments, the preheated condition may be defined bydifferent characteristics or events. For example, the preheatedcondition may correspond to the food item attaining a temperatureapproximately equal to the boiling point of water, or preheating thefood item for a predetermined time.

After the food item attains the preheated condition, the second stage604 begins at step 620, which includes moving the second container tothe upper position within the first container and above the water. Forexample, the second container may be raised to the upper position usingany of the lifting mechanisms or lifting arms described previously.

Step 622 includes boiling the water such that steam from the boilingwater passes through the perforated walls in the second container so asto heat the food item. In some embodiments, the water may already beboiling, for example, when the preheated condition is defined by thecommencement or recommencement of boiling.

Step 630 includes cooking the food item in the steam until the food itemattains a cooked condition. For example, the cooked condition may bedefined by cooking the food item for a predetermined time at apredetermined temperature. Furthermore, the predetermined temperaturemay be the temperature of the steam or a nominal steam temperature.Generally, the steam temperature is approximately the boiling point ofwater, for example, about 100° C.

Some of the embodiments described above provide one or more of thefollowing advantages:

To allow more precise timing of the steaming time required to producedesired results by preheating food to be steamed and starting time countonly when the food is in the steaming stage;

To thaw frozen food and vegetable pieces and raising their internaltemperature uniformly to the cooking temperature before starting thesteaming period;

To heat small and large pieces in a mixture of vegetables uniformly andevenly into the cooking temperature zone before starting the steamingprocess;

To reduce inconsistencies in the taste and texture of steamed food andvegetables;

To produce more uniformly steamed vegetable pieces in a mixture oflarger and smaller pieces;

To reduce over-steaming of small pieces and under steaming-of largerpieces in a mixture of vegetables;

To allow steam cooking of large whole vegetables such as potatoes,mature carrots, beets, yams, cabbage wedges and sweet potatoes; and

To allow more consistent steaming of larger quantities of vegetables.

While the above description provides examples of one or more methodsand/or apparatuses, it will be appreciated that other methods and/orapparatuses may be within the scope of the present description asinterpreted by one of skill in the art.

1. A method of steam cooking, comprising the steps of: a) placing a fooditem in water; b) preheating the food item in the water, by heating thewater, until the food item attains a preheated condition; c) boiling thewater such that steam from boiling water contacts the food item; and d)cooking the food item in steam from the boiling water until the fooditem attains a cooked condition.
 2. The method of claim 1, wherein thepreheated condition is defined by commencement of the water boilingwhile the food item is in the water.
 3. The method of claim 2, whereinthe water is heated so as to boil the water prior to placing the fooditem in the water, and wherein placing the food item in the boilingwater temporarily stop the water from boiling such that the preheatedcondition is defined by recommencement of boiling while the food item isin the water.
 4. The method of claim 1, wherein the preheated conditioncorresponds to the food item attaining a temperature approximately equalto the boiling point of water.
 5. The method of claim 1, wherein thesteam has a nominal steam temperature, and wherein the cooked conditionis defined by cooking the food item for a predetermined time at thesteam temperature.
 6. A method of steam cooking, comprising the stepsof: a) placing water in a first container; b) placing a food item in asecond container configured to retain the food item, the secondcontainer having perforated walls and being sized and shaped to bemoveable within the first container between a lower position and anupper position; c) placing the second container, and the food itemtherein, within the first container in the lower position such that thewater passes through the perforated walls in the second container so asto contact the food item; d) preheating the food item in the water, byheating the water, until the food item attains a preheated condition; e)after the food item attains the preheated condition, moving the secondcontainer to the upper position within the first container and above thewater; f) boiling the water such that steam from boiling water passesthrough the perforated walls in the second container so as to contactthe food item; and g) cooking the food item in the steam until the fooditem attains a cooked condition.
 7. The method of claim 6, wherein thepreheated condition is defined by the commencement of the water boilingwhile the second container is in the lower position such that the fooditem is in the water.
 8. The method of claim 7, wherein the water isheated so as to boil the water prior to placing the food item in thewater, and wherein placing the food item in the boiling watertemporarily stops the water from boiling such that the preheatedcondition is defined by recommencement of boiling while the secondcontainer is in the lower position such that the food item is in thewater.
 9. The method of claim 6, wherein the preheated conditioncorresponds to the food item attaining a temperature approximately equalto the boiling point of water.
 10. The method of claim 6, wherein thesteam has a nominal steam temperature, and wherein the cooked conditionis defined by cooking the food item for a predetermined time at thesteam temperature.
 11. A steaming apparatus comprising: a) a stand sizedand shaped to fit into an opening of a first container configured toretain heated water, the stand having a base for being placed on abottom surface of the first container; b) a second container configuredto retain a food item and having perforated walls, the second containerbeing sized and shaped to fit in the opening of the first container andbeing moveable within the first container between: i) a lower positionsuch that the heated water within the first container passes through theperforated walls so as to heat a food item retained within the secondcontainer; and ii) an upper position such that the second container islocated above the heated water within the first container and steam fromthe heated water passes through the perforated walls so as to heat thefood item retained within the second container; and c) a coupler forcoupling the stand to the second container, the coupler being configuredto allow the second container to move between the upper and lowerposition.
 12. The steaming apparatus of claim 11, further comprising alifter coupled to the second container for raising and lowering thesecond container, and wherein the coupler comprises: a) a verticalmember coupled to an edge of the stand so as to extend upward along aside of the second container, the vertical member having at least onetooth; and b) a detent coupled to the second container for engaging theat least one tooth of the vertical member so as to retain the secondcontainer in a position corresponding to engagement of the detent andthe at least one tooth, wherein the lifter is configured to allow thedetent to selectively engage and disengage the at least one tooth of thevertical member.
 13. The steaming apparatus of claim 12, wherein thelifter is a lifter arm pivotally coupled to the second container, thelifter arm being pivotal between: a) a generally vertical position formoving the second container between the upper and lower positions, andb) a generally horizontal position such that a lid can be placed on thefirst container.
 14. The steaming apparatus of claim 13, furthercomprising a pivot stop for limiting pivotal movement of the lifter armso as to inhibit the lifter arm from pivoting below the generallyhorizontal position.
 15. The steaming apparatus of claim 11, wherein thecoupler comprises: a) a shaft coupled to a central portion of the standand extending upward through an aperture in the second container, theshaft having at least one tooth; b) a bushing coupled to the secondcontainer and having a hollow end for slidably receiving the shaftthrough the aperture in the second container; c) a detent coupled to thebushing for engaging the at least one tooth of the vertical member so asto retain the second container in a position corresponding to engagementof the detent and the at least one tooth; and d) a lifter coupled to thebushing for sliding the bushing along the shaft so as to raise and lowerthe second container between the upper and lower positions when thedetent disengages the at least one tooth.
 16. The steaming apparatus ofclaim 15, wherein the second container is an adjustable size container.17. The steaming apparatus of claim 15, further comprising a leaf springhaving one end coupled to an outer surface of the bushing, and anotherend coupled to the detent, wherein the bushing has an opening forallowing the detent to selectively engage and disengage the at least onetooth of the shaft through the opening in the bushing, and wherein theleaf spring biases the detent toward engagement with the at least onetooth.
 18. The steaming apparatus of claim 15, wherein the bushingslidably and rotatable receives the shaft, such that the detent isrotatable between: a) an engaged position wherein the detent engages theat least one tooth; b) a disengaged position wherein the detentdisengages the at least one tooth and the bushing is slidable along theshaft for moving the second container between the upper and lowerpositions.
 19. An automatic steaming apparatus comprising: a) a firstcontainer configured to retain heated water and having a rim defining anopening; b) a second container configured to retain a food item andhaving perforated walls, the second container being sized and shaped tofit in the opening of the first container and being moveable within thefirst container between: i) a lower position such that the heated waterwithin the first container passes through the perforated walls so as toheat a food item retained within the second container; and ii) an upperposition such that the second container is located above the heatedwater within the first container and steam from the heated water passesthrough the perforated walls so as to heat the food item retained withinthe second container; and c) a lifter mechanism coupled to the first andsecond containers for automatically moving the second container from thelower position to the upper position after the heated water within thefirst container preheats the food item to a preheated condition.
 20. Theapparatus of claim 19, further comprising a temperature sensor incommunication with the lifter mechanism and configured to measure thetemperature of the water in the first container, and wherein thepreheated condition corresponds to the temperature sensor measuring atemperature approximately equal to the boiling point of water.
 21. Theapparatus of claim 19, wherein the lifter mechanism comprises: a) ashaft coupled to the first container and having a threaded portion forengaging the an internal thread on the second container; and b) a motorfor rotating the shaft in one direction so as to raise the secondcontainer to the upper position, and for rotating the shaft in anopposite direction so as to lower the second container to the lowerposition.
 22. A steaming apparatus comprising: a) a first containerconfigured to retain heated water and having a rim defining an opening;b) a second container configured to retain a food item and havingperforated walls, the second container being sized and shaped to fit inthe opening of the first container and being moveable within the firstcontainer between: i) a lower position such that the heated water withinthe first container passes through the perforated walls so as to heat afood item retained within the second container; and ii) an upperposition such that the second container is located above the heatedwater within the first container and steam from the heated water passesthrough the perforated walls so as to heat the food item retained withinthe second container; and c) a handle coupled to the second containerfor moving the second container between the lower position and the upperposition, wherein the handle includes a stepped portion configured to atleast partially retain the second container in the upper position. 23.The steaming apparatus of claim 22, wherein the handle comprises a hookfor engaging the rim of the first container so as to at least partiallyretain the second container in the upper position.